It has been found that the fuel induction system, valves, and combustion chambers of internal combustion engines develop deposits which are derived from many sources, including materials in the fuel, products of fuel decomposition, products of fuel combustion, contaminants in the air which are not removed by filtration, and lubricating oil residues. Such deposits lead to poor distribution of the fuel charge in the cylinder, inappropriate quantities of fuel in the various cylinders, and other problems which lead to poor engine performance, increased emissions, and poor fuel economy.
Accordingly, it is an object of this invention to provide cleaning compositions which will both remove fuel induction system deposits, as well remove deposits from the valves and combustion chambers. The compositions are not intended to be used in the fuel itself, but are intended to be used as a single cleaning treatment of the engine.
U.S. Pat. No. 2,952,637 discloses a carburetor and engine cleaning composition containing an alkoxy alcohol, an aliphatic alcohol, a petroleum distillate, a liquid fatty acid, a volatile nitrogen base and water. As shown in Example 4, this composition does not provide adequate cleaning in a test designed to simulate cleaning of valve deposits. In the U.S. Pat. No. 2,952,637, the volatility of the nitrogen base is important to the invention. Hydroxyalkylamines, such as ethanolamines, are to be avoided because of their low volatility and their tendency to cause sludge to deposit in the ring grooves of the piston.
U.S. Pat. No. 3,876,704 discloses that N-long chain alkyl, N-hydroxyalkyl alkylenepolyamines are useful as detergents in hydrocarbon fuels.
U.S. Pat. No. 4,055,402 discloses that polyisobutenyl aminoethylethanolamine is useful as a gasoline detergent at levels from 50 to 200 parts per million.